The long term objective is to develop and market high sensitivity and market high sensitivity microscope systems for imaging ocular tissues, in vivo. Specific aims for this project are: 1. to design, construct, and test high numerical aperture lenses for imaging the anterior and posterior crystalline lens epithelial cells and lens fibers, in vivo, 2. To investigate the feasibility of a high NA, diffraction limited lens system, with strong optical sectioning characteristics, for imaging the posterior retina, in vivo, 3. To develop optical designs of contact elements that will enhance the contrast and detail in images of superficial epithelial cells,and 4. To refine the precision of critical components of the optical system so that the full capabilities for optical sectioning and resolution are available to research and clinical users. The study of cataract formation and the influence of various drugs should be facilitated by the high resolution images and the ability to follow subjects over extended time periods. Retinal images with strong optical sectioning and high resolution will be useful for studies of the macula, the nerve, fiber layer, the disc, and research on retinal cell transplantation. The early diagnosis of infectious corneal diseases such as Acanthamoeba and fungus is a continuing goal. Proposed Commercial Applications: An instrument for research and clinical studies of the crystalline lens, the cornea, and the retina. It extends the capabilities of the slit lamp by its increased resolution, optical sectioning capability, and enhanced sensitivity for detection of faint detail in nominally transparent tissues. Early diagnosis of corneal disease is a particularly promising application.